A cage of the above type is known from U.S. Pat. No. 5,255,985. For the installation of cages of this type in double rim bearings, as shown for example on Page 107 of INA Catalogue 306, the cylindrical rolling elements are pushed into the cage in radial direction from the inside to the outside. During this procedure, it often happens that the cage and the rolling elements are offset from one another i.e., there is no axial correspondence of position between the cage pocket and the rolling element, so that the rolling elements project beyond the axial length of the pockets into the region of the side rings of the cage. The side rings of the cage are damaged during the radial insertion of the rolling elements and spalling or tearing-out of the material of the cage occurs which can lead to a high reject rate of the bearings if the broken-off material penetrates into the raceway region. In the case of sleeve bearings i.e., bearings with very narrow rims, there exists the additional danger of the cage protruding beyond the rims in axial direction.
Another drawback of such cage and rolling element assemblies is the frequently occurring large rolling element sag i.e., the rolling elements fall downwards within the pockets due to the force of gravity so that a gap is formed between their rolling surface and the outer raceway. Due to this sag, the end face of a shaft introduced into the bearing comes to abut against the end faces of individual cylindrical rollers or against the end faces of the side rings of the cage itself which means that the insertion of the shaft is rather problematic so that an automatic assembly is rendered more difficult.